A comprehensive analysis of verbal fluency deficit in geriatric schizophrenia

Polygenic risk for schizophrenia and the language network: Putative compensatory reorganization in unaffected siblings

Language-related symptoms, such as disorganized, impoverished speech and communicative behaviors, are one of the core features of schizophrenia. These features most strongly correlate with cognitive deficits and polygenic risk among various symptom dimensions of schizophrenia. Nevertheless, unaffected siblings with genetic high-risk fail to show consistent deficits in language network (LN), indicating that either (1) polygenic risk has no notable effect on LN and/or (2) siblings show compensatory changes in opposing direction to patients. To answer this question, we related polygenic risk scores (PRS) to the region-level, tract-level, and systems-level structure (cortical thickness and fiber connectivity) of LN in 182 patients, 48 unaffected siblings and 135 healthy controls. We also studied the relationships between symptoms, language-related cognition, social functioning and LN structure. We observed a significantly lower thickness in LN (especially the Broca's, Wernicke's area and their right homologues) in patients. Siblings had a distinctly higher thickness in parts of the LN and a more pronounced small-world-like structural integration within the LN. Patients with reduced LN thickness had higher PRS, more disorganization and impoverished speech with lower language-related cognition and social functioning. We conclude that the genetic susceptibility and putative compensatory changes for schizophrenia operate, in part, via key regions in the Language Network.

Neurocognitive and linguistic correlates of positive and negative formal thought disorder: A meta-analysis

Executive dysfunction and language impairment are the most prominent neuropsychological models of formal thought disorder (FTD) in schizophrenia. However, available studies have provided contradictory findings regarding the accuracy of these models. Furthermore, specific neurocognitive underpinnings of positive FTD (PosFTD) and negative FTD (NegFTD) are not clear. Following the systematic review of schizophrenia studies, a random-effects meta-analysis of the relationship between FTD and neurocognition/language in schizophrenia was conducted in 52 reports including 2805 patients. Neurocognition was significantly associated with both PosFTD (r = -0.21, CI = -0.14 to -0.27) and NegFTD (r = -0.24, CI = -0.18 to -0.30). Both PosFTD (r = ranged from -0.18 to -0.27) and NegFTD (r = ranged from -0.19 to -0.23) were significantly correlated with verbal memory, visual memory, attention, and processing speed. In meta-analyses of executive functions, PosFTD was significantly associated with working memory (r = -0.21), planning (r = -0.19), and inhibition (r = -0.21) and NegFTD was significantly associated with planning (r = -0.27), fluency (r = -0.27), and working memory (r = -0.24). In meta-analyses of linguistic variables, PosFTD was associated with deficits in syntactic comprehension (r = -0.27) and semantic processing (r = -0.18). In contrast, NegFTD was associated only with semantic comprehension (r = -0.21). Both PosFTD and NegFTD were significantly associated with executive dysfunction, neurocognitive deficits and semantic dysfunction but syntactic deficits were more specific to PosFTD. There were also some distinct patterns of relationships between the pattern of executive dysfunction and types of FTD. Fluency deficit was associated more strongly with NegFTD and poor inhibition was more specifically related to PosFTD. Current findings suggest that neurocognitive and linguistic correlates of PosFTD and NegFTD might be partly different.

Speech-language intervention in schizophrenia: an integrative review

ABSTRACT Objective: to perform an integrative review to identify speech and language pathology intervention for schizophrenia. Methods: the review covered SCIELO, PUBMED, OXFORD JOURNALS and SCIENCEDIRECT databases for speech and language pathology intervention studies for schizophrenia. A narrative synthesis was adopted considering the level of clinical and methodological heterogeneity amid studies. Results: the results demonstrated an increase in publications since 2012 with 11 articles meeting the criteria. Language and discourse assessment were the speech and language pathology privileged procedures. Conclusion: the review indicates that the most eligible intervention was assessment, that studies’ methodology were heterogeneous and that the communication disorders identified were related to discursive, pragmatic and syntactic disorders, which evidences the importance of more systematized intervention procedures and research on schizophrenic patients.

Validation of the Korean Version of the Clinical Assessment Interview for Negative Symptoms

OBJECTIVE

Clinical Assessment Interview for Negative Symptoms (CAINS) has recently been developed to improve measurement of negative symptoms in schizophrenia. We performed a multi-center study to validate the Korean version of the CAINS (CAINS-K) and explore potential cultural variation.

METHODS

One hundred eighty schizophrenia patients diverse in demographic and illness profile were recruited from four centers in Korea. Along with the CAINS-K, the Scale for the Assessment of Negative Symptoms (SANS), Brief Psychiatric Rating Scale (BPRS), Calgary Depression Scale for Schizophrenia (CDSS), a self-report measure of behavioral inhibition and activation (BIS/BAS) and neurocognitive tasks were administered to verify external validities.

RESULTS

The CAINS-K showed high internal-consistency (0.92) and inter-rater reliability (0.77). Exploratory Factor Analysis replicated a two-factor structure of the original scale including motivation/pleasure and expression deficits dimensions. Korean patients tended to report lower pleasure compared to American patients in the prior study. The CAINS-K showed an adequate convergent validity with the SANS, negative symptoms of the BPRS, and BAS. A divergent validity was supported as the CAINS-K showed zero or only weak correlations with other symptoms of the BPRS, depression from the CDSS, and neurocognitive tasks.

CONCLUSION

The CAINS-K demonstrated high internal consistency and adequate external validities, and is expected to promote studies on negative symptoms in Korean patients with schizophrenia.

The current conceptualization of negative symptoms in schizophrenia

Negative symptoms have long been conceptualized as a core aspect of schizophrenia. They play a key role in the functional outcome of the disorder, and their management represents a significant unmet need. Improvements in definition, characterization, assessment instruments and experimental models are needed in order to foster research aimed at developing effective interventions. A consensus has recently been reached on the following aspects: a) five constructs should be considered as negative symptoms, i.e. blunted affect, alogia, anhedonia, asociality and avolition; b) for each construct, symptoms due to identifiable factors, such as medication effects, psychotic symptoms or depression, should be distinguished from those regarded as primary; c) the five constructs cluster in two factors, one including blunted affect and alogia and the other consisting of anhedonia, avolition and asociality. In this paper, for each construct, we report the current definition; highlight differences among the main assessment instruments; illustrate quantitative measures, if available, and their relationship with the evaluations based on rating scales; and describe correlates as well as experimental models. We conclude that: a) the assessment of the negative symptom dimension has recently improved, but even current expert consensus-based instruments diverge on several aspects; b) the use of objective measures might contribute to overcome uncertainties about the reliability of rating scales, but these measures require further investigation and validation; c) the boundaries with other illness components, in particular neurocognition and social cognition, are not well defined; and d) without further reducing the heterogeneity within the negative symptom dimension, attempts to develop successful interventions are likely to lead to great efforts paid back by small rewards.

The current conceptualization of negative symptoms in schizophrenia

Negative symptoms have long been conceptualized as a core aspect of schizophrenia. They play a key role in the functional outcome of the disorder, and their management represents a significant unmet need. Improvements in definition, characterization, assessment instruments and experimental models are needed in order to foster research aimed at developing effective interventions. A consensus has recently been reached on the following aspects: a) five constructs should be considered as negative symptoms, i.e. blunted affect, alogia, anhedonia, asociality and avolition; b) for each construct, symptoms due to identifiable factors, such as medication effects, psychotic symptoms or depression, should be distinguished from those regarded as primary; c) the five constructs cluster in two factors, one including blunted affect and alogia and the other consisting of anhedonia, avolition and asociality. In this paper, for each construct, we report the current definition; highlight differences among the main assessment instruments; illustrate quantitative measures, if available, and their relationship with the evaluations based on rating scales; and describe correlates as well as experimental models. We conclude that: a) the assessment of the negative symptom dimension has recently improved, but even current expert consensus-based instruments diverge on several aspects; b) the use of objective measures might contribute to overcome uncertainties about the reliability of rating scales, but these measures require further investigation and validation; c) the boundaries with other illness components, in particular neurocognition and social cognition, are not well defined; and d) without further reducing the heterogeneity within the negative symptom dimension, attempts to develop successful interventions are likely to lead to great efforts paid back by small rewards.

Using poverty of speech as a case study to explore the overlap between negative symptoms and cognitive dysfunction

BACKGROUND

Negative symptoms and cognitive impairment are both regarded as important prognostic markers in schizophrenia. Although these two domains are viewed as distinct and separable, conceptual overlap exists. We sought to illustrate this overlap using speech deficits among patients with schizophrenia.

METHOD

Reductions in verbal output were rated by a clinician following an interview, and these ratings were taken to represent negative symptoms (i.e., alogia). Patients were also asked to recount words from specific categories in a standardized manner, and the number of words was recorded as per standard protocol for verbal fluency tests. These scores were taken to represent cognitive impairment. The cross-sectional and longitudinal relationships between these two variables were then examined.

RESULTS

Patients with more severe alogia produced significantly less words on the verbal fluency tests. This relationship was stronger than that observed with other negative symptoms, and also held after controlling for a number of sociodemographic and clinical variables (e.g., severity of illness). Prospective increases in the number of words produced during the verbal fluency test were associated with improvements in clinical alogia ratings, a longitudinal relationship that was not observed with other negative symptoms.

CONCLUSIONS

Some negative symptoms are conceptually related and therefore not fully distinct from cognitive impairments. Here, we demonstrate that clinical ratings of alogia and words produced during a cognitive test are tapping into a similar construct. Whether a specific deficit is classified as a negative versus cognitive symptom may be matter of semantics rather than reflective of divisible underlying processes.

Measuring negative symptoms in patients with schizophrenia: reliability and validity of the Korean version of the Motivation and Pleasure Scale-Self-Report

BACKGROUND

The Clinical Assessment Interview for Negative Symptoms (CAINS) is one of the validated interview measures of negative symptoms in psychotic disorders. The Motivation and Pleasure Scale-Self-Report (MPSR) is a self-report measure that assesses the motivation and pleasure domains of negative symptoms based on the CAINS. This study evaluated the reliability and validity of a Korean version of the MPSR.

METHODS

A total of 139 patients with schizophrenia completed the MPSR, CAINS, Scale for the Assessment of Negative Symptoms (SANS), Brief Psychiatric Rating Scales, Calgary Depression Scale for Schizophrenia, and other measures of trait and cognitive function.

RESULTS

The 15-item MPSR showed good internal consistency. In addition, it also had a good convergent validity with the Motivation and Pleasure subscale of the CAINS and the anhedonia/avolition subscale of the SANS. The scale was not associated with psychotic symptoms, agitation/mania, and depression/anxiety, and it showed good discriminant validity. MPSR scores were significantly correlated with Behavioral Activation System total score for trait measure.

CONCLUSION

The Korean version of the MPSR is a notable self-report method for examining the severity of negative symptoms in schizophrenia.

Verbal fluency, clustering, and switching in patients with psychosis following traumatic brain injury (PFTBI)

Verbal fluency in patients with psychosis following traumatic brain injury (PFTBI) has been reported as comparable to healthy participants. This finding is counterintuitive given the prominent fluency impairments demonstrated post-traumatic brain injury (TBI) and in psychotic disorders, e.g. schizophrenia. We investigated phonemic (executive) fluency (3 letters: 'F' 'A' and 'S'), and semantic fluency (1 category: fruits and/or vegetables) in four matched groups; PFTBI (N=10), TBI (N=10), schizophrenia (N=23), and healthy controls (N=23). Words produced (minus perseverations and errors), and clustering and switching scores were compared for the two fluency types across the groups. The results confirmed that PFTBI patients do show impaired fluency, aligned with existing evidence in TBI and schizophrenia. PFTBI patients produced the least amount of words on the phonemic fluency ('A') trial and total score, and demonstrated reduced switching on both phonemic and semantic tasks. No significant differences in clustering performance were found. Importantly, the pattern of results suggested that PFTBI patients share deficits with their brain-injured (primarily executive), and psychotic (executive and semantic), counterparts, and that these are exacerbated by their dual-diagnosis. These findings add to a very limited literature by providing novel evidence of the nature of fluency impairments in dually-diagnosed PFTBI.

Long-term course of cognitive function in chronically hospitalized patients with schizophrenia transitioning to community-based living

Schizophrenia is associated with impairments in social interactions, and the conditions under which patients live and undergo treatment appear to have an important role in the course of the disease. However, the influences of care settings on the course of cognition remain controversial. The closure of psychiatric hospitals and the transition to community-based living is a golden opportunity to address this issue. The aims of the present study were to examine (1) the longitudinal course of cognition as well as the psychopathology and social functioning of schizophrenia patients who had been chronically hospitalized and then discharged, and (2) the key cognitive predictors of the functional outcome of such patients. Seventy-eight patients were transferred to the community after the closure of a psychiatric hospital. These patients were followed-up for 5 years and underwent annual examinations that included measures of cognition, psychiatric symptoms, and social functioning. Fifty-six patients completed all the assessments. Although consistent improvements were shown in the cognitive domains for attention and memory, the initial improvements in global cognition and processing speed ultimately began to decline. Symptoms and global functioning improved almost consistently over the course of the follow-up period. Stepwise multiple regressions revealed category fluency at baseline predicted social functioning at 5 years. However, this correlation was no longer significant when psychopathological variables were included as predictors. These results suggest that care settings affect the course of cognition, and addressing these conditions may lead to a certain degree of cognitive improvement even among schizophrenia patients who have been chronically institutionalized.

Latent semantic variables are associated with formal thought disorder and adaptive behavior in older inpatients with schizophrenia

INTRODUCTION

Formal thought disorder is a hallmark feature of schizophrenia in which disorganized thoughts manifest as disordered speech. A dysfunctional semantic system and a disruption in executive functioning have been proposed as possible mechanisms for formal thought disorder and verbal fluency impairment. Traditional rating scales and neuropsychological test scores might not be sensitive enough to distinguish among types of semantic impairments. This has lead to the proposed used of a natural language processing technique, Latent Semantic Analysis (LSA), which offers improved semantic sensitivity.

METHOD

In this study, LSA, a computational, vector-based text analysis technique to examine the contribution of vector length, an LSA measure related to word unusualness and cosines between word vectors, an LSA measure of semantic coherence to semantic and phonological fluency, disconnectedness of speech, and adaptive functioning in 165 older inpatients with schizophrenia.

RESULTS

In stepwise regressions word unusualness was significantly associated with semantic fluency and phonological fluency, disconnectedness in speech, and impaired functioning, even after considering the contribution of premorbid cognition, positive and negative symptoms, and demographic variables.

CONCLUSIONS

These findings support the utility of LSA in examining the contribution of coherence to thought disorder and the its relationship with daily functioning. Deficits in verbal fluency may be an expression of underlying disorganization in thought processes.

Reduced prefrontal cortex activation during divergent thinking in schizophrenia: a multi-channel NIRS study

Relationships between deficits in verbal fluency and poor social functioning have been revealed in patients with schizophrenia. In previous studies, we demonstrated that deficits in idea fluency, which is ranked as a more complex type of verbal fluency and reflects divergent thinking ability, were more closely related to social dysfunction than deficits in simple word fluency. Although functional neuroimaging studies have provided detailed data regarding prefrontal dysfunction during word fluency tasks, the regions that relate to deficits in fluency of ideas and thoughts have not yet been clarified in schizophrenia patients. The purpose of the present study was to identify the prefrontal sub-regions responsible for deficits in idea fluency using near-infrared spectroscopy (NIRS), which is more practical than other imaging methods, and to investigate the relationships between lesions and idea fluency deficits and social dysfunction in patients with schizophrenia. Eighteen outpatients with schizophrenia and 16 healthy subjects were recruited for this case-controlled study. Using 24-channel NIRS, we measured changes in hemoglobin concentration in the prefrontal cortical surface area during idea and letter fluency tests. The analyses revealed that schizophrenia patients generally exhibited a smaller increase in the concentration of oxyhemoglobin in the frontopolar region than the controls during both the tests. However, the areas in which reduced activations were demonstrated in the patients differed remarkably between the idea and letter fluency tests: reduced activations were observed in the ventral region during the former test and in the dorsal region of the frontopolar cortex during the latter test. The reduced activations in each sub-region appeared to affect the related cognitive impairment, since the patients showed significant poorer performances than the controls on both the tests. Moreover, hypoactivity during idea fluency was significantly correlated with poor social functioning as assessed using the Global Assessment of Functioning (GAF) in the patient group. The results of the present study suggest that the ventral region within the frontopolar cortex is responsible for divergent thinking, which is associated with poor social functioning in patients with schizophrenia.

Disorganization and reality distortion in schizophrenia: a meta-analysis of the relationship between positive symptoms and neurocognitive deficits

BACKGROUND

Factor analytic studies have shown that in schizophrenia patients, disorganization (e.g., conceptual disorganization and bizarre behavior) is a separate dimension from other types of positive symptoms such as reality distortion (delusions and hallucinations). Although some studies have found that disorganization is more strongly linked to neurocognitive deficits and poor functional outcomes than reality distortion, the findings are not always consistent.

METHODS

A meta-analysis of 104 studies (combined n=8015) was conducted to determine the magnitude of the relationship between neurocognition and disorganization as compared to reality distortion. Additional analyses were conducted to determine whether the strength of these relationships differed depending on the neurocognitive domain under investigation.

RESULTS

The relationship between reality distortion and neurocognition was weak (r=-.04; p=.03) as compared to the moderate association between disorganization and neurocognition (r=-.23; p<.01). In each of the six neurocognitive domains that were examined, disorganization was more strongly related to neurocognition (r's range from -.20 to -.26) than to reality distortion (r's range from .01 to -.12).

CONCLUSIONS

The effect size of the relationship between neurocognition and disorganization was significantly larger than the effect size of the relationship between neurocognition and reality distortion. These results hold across several neurocognitive domains. These findings support a dimensional view of positive symptoms distinguishing disorganization from reality distortion.

Verbal fluency in the detection of mild cognitive impairment and Alzheimer's disease among Brazilian Portuguese speakers: the influence of education

BACKGROUND

Verbal fluency (VF) tasks are simple and efficient clinical tools to detect executive dysfunction and lexico-semantic impairment. VF tasks are widely used in patients with suspected dementia, but their accuracy for detection of mild cognitive impairment (MCI) is still under investigation. Schooling in particular may influence the subject's performance. The aim of this study was to compare the accuracy of two semantic categories (animals and fruits) in discriminating controls, MCI patients and Alzheimer's disease (AD) patients.

METHODS

178 subjects, comprising 70 controls (CG), 70 MCI patients and 38 AD patients, were tested on two semantic VF tasks. The sample was divided into two schooling groups: those with 4-8 years of education, and those with 9 or more years.

RESULTS

Both VF tasks - animal fluency (VFa) and fruits fluency (VFf) - adequately discriminated CG from AD in the total sample (AUC = 0.88 +/- 0.03, p < 0.0001) and in both education groups, and high educated MCI from AD (VFa: AUC = 0.82 +/- 0.05, p < 0.0001; VFf: AUC = 0.85 +/- 0.05, p < 0.0001). Both tasks were moderately accurate in discriminating CG from MCI (VFa: AUC = 0.68 +/- 0.04, p < 0.0001; VFf: AUC = 0.73 +/- 0.04, p < 0.0001) regardless of the schooling level, and MCI from AD in the total sample (VFa: AUC = 0.74 +/- 0.05, p < 0.0001; VFf: AUC = 0.76 +/- 0.05, p < 0.0001). Neither of the two tasks differentiated low educated MCI from AD. In the total sample, fruits fluency best discriminated CG from MCI and MCI from AD; a combination of the two improved the discrimination between CG and AD.

CONCLUSIONS

Both categories were similar in discriminating CG from AD; the combination of both categories improved the accuracy for this distinction. Both tasks were less accurate in discriminating CG from MCI, and MCI from AD.

Symptoms as mediators of the relationship between neurocognition and functional outcome in schizophrenia: a meta-analysis

BACKGROUND

Neurocognitive functioning in schizophrenia has received considerable attention because of its robust prediction of functional outcome. Psychiatric symptoms, in particular negative symptoms, have also been shown to predict functional outcome, but have garnered much less attention. The high degree of intercorrelation among all of these variables leaves unclear whether neurocognition has a direct effect on functional outcome or whether that relationship to functional outcome is partially mediated by symptoms.

METHODS

A meta-analysis of 73 published English language studies (total n=6519) was conducted to determine the magnitude of the relationship between neurocognition and symptoms, and between symptoms and functional outcome. A model was tested in which symptoms mediate the relationship between neurocognition and functional outcome. Functional outcome involved measures of social relationships, school and work functioning, and laboratory assessments of social skill.

RESULTS

Although negative symptoms were found to be significantly related to neurocognitive functioning (p<.01) positive symptoms were not (p=.97). The relationship was moderate for negative symptoms (r=-.24, n=4757, 53 studies), but positive symptoms were not at all related to neurocogniton (r=.00, n=1297, 25 studies). Negative symptoms were significantly correlated with functional outcome (r=-.42, p<.01), and again the correlation was higher than for positive symptoms (r=-.03, p=.55). Furthermore, our findings support a model in which negative symptoms significantly mediate the relationship between neurocognition and functional outcome (Sobel test p<.01).

CONCLUSIONS

Although neurocognition and negative symptoms are both predictors of functional outcome, negative symptoms might at least partially mediate the relationship between neurocognition and outcome.

Contribution of divergent thinking to community functioning in schizophrenia

Fluency deficits have been associated with poor community functioning in patients with schizophrenia. In our previous study we demonstrated that the ability to generate higher-quality responses on tasks of divergent thinking as measured by several fluency tests was impaired in patients with schizophrenia. The purpose of the present study was to investigate the contribution of the deficits in divergent thinking to community dysfunction in schizophrenia. Forty Japanese outpatients with schizophrenia and 32 healthy control subjects were recruited for this study and assessed over a broad spectrum of the neurocognitive domain. Their capacity for divergent thinking was assessed by idea, design, and word fluency tests. Community functioning was assessed by using the Global Assessment of Functioning (GAF), the Life Assessment Scale for the Mentally Ill (LASMI), and the Social Functioning Scale (SFS). The results confirmed the qualitative deficits of divergent thinking in schizophrenia. Stepwise multiple regressions using neurocognitive and demographic/clinical variables as predictors revealed that the higher-quality response scores on the tasks of divergent thinking significantly contributed to community functioning. Moreover, the deficit on the verbal task of divergent thinking significantly contributed to impairment in the area of daily living, and the deficit on the nonverbal task of divergent thinking significantly contributed to impairment in the area of interpersonal relations. The results of this study reveal the importance and the possibility of cognitive remediation and cognitive training with strategies that target capacity for divergent thinking to improve community functioning in patients with schizophrenia.

Verbal fluency impairments among middle-aged and older outpatients with schizophrenia are characterized by deficient switching

Patients with schizophrenia demonstrate impaired verbal fluency, but no studies have examined the underlying cognitive mechanisms (e.g., clustering and switching) associated with impaired fluency among middle-aged and older, non-institutionalized patients. Using Troyer et al.'s [Troyer, A.K., Moscovitch, M., Winocur, G., 1997. Clustering and switching as two components of verbal fluency: evidence from younger and older healthy adults. Neuropsychology 11 (1), 138-146] conceptual model, we examined clustering and switching on verbal fluency tasks among 163 middle-aged and older outpatients with schizophrenia and 92 age comparable healthy comparison (HC) participants. The patients produced significantly fewer total words than HC participants on both the letter ("F", "A", "S") and Animal fluency conditions. With regard to clustering, patients were similar to HC participants on both FAS and Animal fluency tasks. However, significantly fewer switches between lexical-semantic categories were observed among patients with schizophrenia on both conditions relative to HC participants. A small, but statistically significant association was found between number of switches on the Animal fluency task and severity of negative symptoms. The absence of a difference in mean cluster size between the patient and HC groups suggests intact lexical-semantic stores among middle-aged and older outpatients with schizophrenia. Differences in switching between patients and HC participants may be driven by several cognitive impairments associated with schizophrenia. Further delineation of the cognitive mechanisms of the observed lexical-semantic switching deficits in schizophrenia should be a focus of future research.

Does negative symptom change relate to neurocognitive change in schizophrenia? Implications for targeted treatments

Negative symptoms and cognitive dysfunction are among the most challenging obstacles in the treatment of schizophrenia. It is unknown to what extent they are overlapping or independent disease processes. In the search for targeted treatments of negative symptoms and cognitive impairments, it is imperative to determine their longitudinal relationship. 267 stable outpatients with schizophrenia in a work and cognitive rehabilitation program were evaluated using symptom measures and a comprehensive neuropsychological test battery at baseline and at the conclusion of rehabilitation, 6 months later. Baseline negative symptom, neuropsychological variables and change scores from intake to follow-up on these variables were correlated. These analyses were repeated with a subsample (n = 161) who had clinically significant negative symptoms at baseline. ANCOVA's were performed to compare patients whose negative symptoms improved by 5 points or more (n = 69) with those whose negative symptoms got worse by 5 points or more (n = 26) on their neurocognitive performance at follow-up. Intake negative symptoms were significantly associated with theory of mind and visuomotor processing. Results failed to support a lawful relationship between change in negative symptoms and neurocognition. These findings suggest that negative symptoms and neurocognition should be viewed as relatively independent targets for intervention.

Easier tasks can have better discriminating power: the case of verbal fluency

Loren and Jean Chapman highlighted the importance that the psychometric characteristics of a task may have when comparing different populations (L. J. Chapman & J. P. Chapman, 1973, 1978). Specifically, they pointed out that when comparing 2 tasks measuring different constructs, there is a greater likelihood of finding larger deficits on a task with higher discriminating power, irrespective of what the task measures. While researchers have addressed this issue, they typically have assumed that more difficult tasks have greater discriminating power, often without actually measuring discriminating power. In this article, the authors present data from 2 studies using phonologic and category fluency tasks to demonstrate that the critical factor for task selection and matching is discriminating power, not task difficulty.

Cognition in schizophrenia: impairments, determinants, and functional importance

Recent findings support and add to earlier findings of cognitive dysfunction in schizophrenia. Deficits across neurocognitive domains such as attention, working memory, language skills, and executive functioning tend to be moderate, with the most pronounced deficits found in verbal learning and memory. All these neurocognitive domains are related to adaptive and social skills, with executive functions and verbal learning and memory showing more variance across more domains than other neuro-cognitive variables. Negative symptoms and neurocognitive domains, although correlated, are distinct and have differential pathways of change with treatment. General psychopathology symptoms, such as depression and anxiety, may become important treatment targets as strategies are developed for translating cognitive enhancement to real-world functional performance.